* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: linear-gradient(135deg, #1a2a6c, #b21f1f);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    padding: 20px;
    background-size: 200% 200%;
    animation: gradientBG 15s ease infinite;
}

@keyframes gradientBG {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.nav {
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.9);
    padding: 15px 30px;
    border-radius: 15px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    margin-bottom: 40px;
    backdrop-filter: blur(5px);
}

.nav img {
    height: 50px;
    margin-right: 15px;
    border-radius: 8px;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.1);
}

.blog-title {
    font-size: 28px;
    font-weight: 700;
    color: #1a2a6c;
    letter-spacing: 1px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

.space {
    flex: 1;
}

.nav-span {
    text-decoration: none;
    color: #333;
    font-weight: 600;
    margin-left: 25px;
    padding: 8px 15px;
    border-radius: 8px;
    transition: all 0.3s ease;
    position: relative;
}

.nav-span:hover {
    background: #1a2a6c;
    color: white;
    transform: translateY(-2px);
}

.nav-span::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 3px;
    background: #b21f1f;
    border-radius: 2px;
    transition: width 0.3s ease;
}

.nav-span:hover::after {
    width: 100%;
}

.container-login {
    max-width: 500px;
    width: 100%;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.25);
    backdrop-filter: blur(10px);
    animation: fadeIn 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
    transform: translateY(20px);
    opacity: 0;
}

@keyframes fadeIn {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-dialog {
    padding: 40px;
}

.login-dialog h3 {
    text-align: center;
    font-size: 32px;
    margin-bottom: 30px;
    color: #1a2a6c;
    position: relative;
    padding-bottom: 15px;
}

.login-dialog h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(to right, #1a2a6c, #b21f1f);
    border-radius: 2px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.row {
    margin-bottom: 25px;
    position: relative;
}

.row span {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #444;
    font-size: 16px;
    padding-left: 5px;
}

.row span i {
    margin-right: 8px;
    color: #1a2a6c;
}

.row input {
    width: 100%;
    padding: 14px 20px;
    border: 2px solid #e1e1e1;
    border-radius: 12px;
    font-size: 16px;
    transition: all 0.3s ease;
    background: #f8f9fa;
    box-shadow: inset 0 2px 5px rgba(0, 0, 0, 0.05);
}

.row input:focus {
    border-color: #1a2a6c;
    box-shadow: 0 0 0 3px rgba(26, 42, 108, 0.2), inset 0 2px 5px rgba(0, 0, 0, 0.05);
    outline: none;
    background: white;
}

.input-icon {
    position: absolute;
    right: 20px;
    top: 40px;
    color: #777;
    cursor: pointer;
    transition: color 0.3s;
}

.input-icon:hover {
    color: #b21f1f;
}

#confirm {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-top: 30px;
}

#inputCaptcha {
    flex: 1;
    padding: 12px 15px;
    border: 2px solid #e1e1e1;
    border-radius: 10px;
    font-size: 16px;
    background: #f8f9fa;
    box-shadow: inset 0 2px 5px rgba(0, 0, 0, 0.05);
}

#verificationCodeImg {
    width: 130px;
    height: 50px;
    border-radius: 10px;
    border: 1px solid #ddd;
    background: #f1f3f5;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 3px 8px rgba(0,0,0,0.1);
    position: relative;
    overflow: hidden;
}

#verificationCodeImg::before {
    content: '点击刷新';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(26, 42, 108, 0.8);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s;
    font-size: 12px;
    font-weight: bold;
}

#verificationCodeImg:hover::before {
    opacity: 1;
}

#verificationCodeImg:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(0,0,0,0.15);
}

button {
    width: 100%;
    padding: 16px;
    background: linear-gradient(to right, #1a2a6c, #b21f1f);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    letter-spacing: 1px;
    margin-top: 10px;
    box-shadow: 0 4px 15px rgba(26, 42, 108, 0.3);
    position: relative;
    overflow: hidden;
}

button::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -60%;
    width: 40%;
    height: 200%;
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(30deg);
    transition: all 0.6s;
}

button:hover::after {
    left: 120%;
}

button:hover {
    transform: translateY(-3px);
    box-shadow: 0 7px 20px rgba(26, 42, 108, 0.4);
}

.register-button {
    background: white !important;
    color: #1a2a6c !important;
    border: 2px solid #1a2a6c !important;
    box-shadow: none !important;
}

.register-button:hover {
    background: #f0f4ff !important;
    transform: translateY(-3px) !important;
    box-shadow: 0 4px 10px rgba(26, 42, 108, 0.2) !important;
}

.form-footer {
    text-align: center;
    margin-top: 30px;
    color: #666;
    font-size: 14px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

.form-footer a {
    color: #1a2a6c;
    font-weight: 600;
    text-decoration: none;
    margin: 0 8px;
    transition: all 0.2s;
    position: relative;
}

.form-footer a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: #b21f1f;
    transition: width 0.3s;
}

.form-footer a:hover::after {
    width: 100%;
}

.form-footer a:hover {
    color: #b21f1f;
}

.captcha-hint {
    text-align: center;
    margin-top: 10px;
    color: #777;
    font-size: 13px;
    font-style: italic;
}

.decoration {
    position: absolute;
    z-index: -1;
}

.decoration-1 {
    top: 10%;
    left: 10%;
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: rgba(178, 31, 31, 0.1);
    box-shadow: 0 0 50px rgba(178, 31, 31, 0.2);
}

.decoration-2 {
    bottom: 20%;
    right: 10%;
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: rgba(26, 42, 108, 0.1);
    box-shadow: 0 0 70px rgba(26, 42, 108, 0.2);
}

.decoration-3 {
    top: 40%;
    right: 25%;
    width: 70px;
    height: 70px;
    border-radius: 30% 70% 70% 30% / 30% 30% 70% 70%;
    background: rgba(255, 255, 255, 0.15);
}

/* 响应式设计 */
@media (max-width: 600px) {
    .nav {
        padding: 12px 20px;
        flex-wrap: wrap;
    }

    .blog-title {
        font-size: 22px;
    }

    .nav-span {
        margin-left: 15px;
        font-size: 14px;
        padding: 6px 10px;
    }

    .login-dialog {
        padding: 30px 20px;
    }

    .login-dialog h3 {
        font-size: 26px;
    }

    #confirm {
        flex-direction: column;
    }

    #inputCaptcha, #verificationCodeImg {
        width: 100%;
    }

    .row input {
        padding: 12px 15px;
    }

    button {
        padding: 14px;
        font-size: 16px;
    }
}

@media (max-width: 480px) {
    .nav {
        justify-content: center;
    }

    .blog-title {
        font-size: 20px;
    }

    .space {
        display: none;
    }

    .nav-links {
        width: 100%;
        margin-top: 10px;
        display: flex;
        justify-content: center;
    }

    .container-login {
        border-radius: 15px;
    }
}